A number of pests and parasites can infest or infect domestic animals such as cattle, horses, pigs, sheep and also companion animals such as cats and dogs. These pests and parasites are of great nuisance to both the animals and their owners.
Ectoparasites such as ticks, mites, lice, flies and fleas irritate the animals and can cause disease, either by themselves, or by carrying vector transmitted pathogens.
New economic methods and compositions for the prevention, treatment and control of parasites in warm-blooded animals are constantly being sought.
A new family of insecticide isoxazoline compounds has been described in various patent applications; for example, in US patent application US 2007/0066617, and International Patent applications WO 2007/079162, WO 2009/002809, WO 2009/024541, WO 2009/003075, WO 2010/070068, WO 2010/079077, WO 2011/075591 and WO 2011/124998.
As these isoxazoline compounds have been originally investigated for their use in the agricultural area it is necessary to identify specific formulations that allow their veterinary use, i.e. safe administration to control parasites in animals effectively.
One known and convenient way of administering an ectoparasiticide compound to an animal is the topical localized administration, e.g. as spot-on or pour-on.
However, prior art formulations and conventional topical localized ectoparasiticide formulations that use suggested solvents for isoxazoline compounds have difficulties applying effective amounts of isoxazoline compounds with acceptable cosmetic appearance. Particularly, high volumes of conventional topical localized formulations can result in product run-off and sodden appearances of the fur after administration and high concentration formulations can result in insolubility (crystallization) of the active ingredient, skin irritation as well as undesirable product characteristics, such as poor viscosity, insufficient spreading, poor evaporation and inadequate permeation.
Thus, what is needed in the art, are topical localized formulations of isoxazoline compounds, which avoid the drawbacks mentioned above.